The invention relates to the control of passive explosive projectiles fired at a target. The projectiles are provided with means for automatic guidance toward the target or automatic explosion at a given distance from the target.
Known passive homing devices include homing devices which operate at IR wavelengths. In this case the inherant radiation from the target is detected. Passive systems operating at other wavelengths utilize radiation which is reflected from a target exposed to incident radiation from the environment. However, this results in weak and unreliable guidance information. In order to increase the accuracy of aim for passive homing systems it is known to illuminate a target with electromagnetic energy, for example laser light.
A drawback with conventional illumination techniques is the difficulty in reaching the target with the transmitted illuminating energy. If the transmitter must be situated at a large distance from the target, the effect of the illumination will be poor and the power demand in the transmitter will be high. If the transmitter is placed close to the target and then, as usually is the case, is included in a larger unit, for example in an airplane flying over the target, it will expose itself to counter-fire. As a result of this the full range of the projectile can in many cases not be utilized.